Latching mechanism for printing machines

ABSTRACT

A printing machine which has a bed for supporting printing devices and a form to be imprinted, includes a print head pivotally mounted on a base for movement between an open position and a selected closed position. A carriage supporting a platen is mounted on the print head and the carriage is movable in a path from a home position across the bed to an actuated position to perform a printing stroke, and back to the home position in readiness for a subsequent printing operation. Means is provided for sensing the thickness of the form to be imprinted, and a latching mechanism is provided for latching the print head in closed position, which in fact is a position selected from an infinite number of possible positions within a range as determined by the sensed thickness of the form. The print head is held in the selected closed position during a printing stroke and is restored to its open position prior to return of the carriage to the home position.

United States Patent 1191 I Miller et al.

[ 4] LATCHING MECHANISM FOR PRINTING I MACHINES [75 Inventors: John P. Miller, Chardon; Arthur W.

Oatess, Cleveland; Bryce G. Thornton, Mentor, all of Ohio [73] Assignee: Addressograph-Multigraph Corporation, Cleveland, Ohio [22] Filed; Nov. 20, 1972 [21] Appl. No.: 308,070

[52] US. Cl. 101/269 [51] Int. Cl 1341f 3/20 [58] Field of Search..... l'0l/56, 269, 283, 252, 256,

[56] References Cited UNITED STATES PATENTS 3,228,326 l/l966 Childress 101 114 1,801,595 4 1931 Dugdale..... 101/269 x 2,092,026 9 1937 Schaefer.... 10l/56 2,176,371 10/1939 Wahl 101 269 2,587,612 3 1952 Gilbert... 101 269 2,620,729 12/1952 Gilbert 101 269 2,935,939 5/1960 Dohertyet al 101/269 2,982,205 5/1961 Maul... 101/269 1 Mar. 5,1974

3,447, 58 6/1969 Yow-Jiun 1111...; l0l/269 Primary Examiner-4. Reed Fisher Assistant Examiner-Paul J. Hirsch Attorney, Agent, or FirmRay S. Pyle [5 7] ABSTRACT A printing machine which has a bed for supporting printing devices and a form to be imprinted, includes a print head pivotally mounted on a base for movement between an open position and a selected closed position. A carriage supporting a platen is mounted on the print head and the carriage is movable in a path from a home position across the bed to an actuated position to perform a printing stroke; and back to the home position in readiness for a subsequent printing operation Means is provided for sensing the thicknessof the form to be imprinted, and a latching mechanism is provided for latching the print head in closed position, which in fact is a position selected from an infinite number of possible positions within a range as determined by the sensed thickness of the form. The print head is held in the selected closed position during a printing stroke and is restored to its open position prior to return of the carriage t0 the home posi- 4 Claims, 6 Drawing Figures Ill/ml I LATCHING MECHANISM FOR PRINTING- MACHINES PRIOR ART Refer to co-pending application Ser. No. 92,754, filed Nov. 25, i970, assigned to the assignee of the present application, for a related invention.

BACKGROUND OF THE INVENTION Although present day data recorders are well suited to imprinting documents in a legible, accurate manner, it has been found that a wide variety of data recorders are required in order to meet the requirements of the many different applications. One of the major difficulties in attempting to provide a standardized datarecorder for use in various applications is that the forms to be imprinted and/or the embossed cards differ in thickness.

It will be appreciated that in recording certain types of business transactions, numerous copies are required for inventory and other bookkeeping purposes. These copies can represent a substantial thickness especially in view of interleaved carbon paper sheets where these are present, together with a tabulating card and an opaque or bond top sheet. In other instances, fewer copies are required so that the thickness of the form set may vary. Accordingly, it is necessary to adjust the platen to a selected printing position spaced from the bed for different thicknesses of forms and cards in order to obtain dense, high quality printed impressions.

Various approaches have been taken to construct a machine of the kind involved in such a manner that clear and legible impressions can be obtained on the copies regardless of the various thicknesses of the forms and the cards. Some of these prior art devices utilize a compensating anvil which is spring loaded to permit movement of the anvil away from the platen as a result of the pressure .applied to the anvil by the platen during a printing operation. However, this arrangement can provide only a limited amount of compensation.

Other devices provide a compensating platen such that the axis of rotation of the platen can be adjusted to accommodate different thicknesses of forms to be imprinted. In this case, it is necessary to manually adjust the platen for each different thickness range of forms and cards.

Another platen compensating arrangement, similar to the present invention in performance but different in construction and operation, is shown in Maul et al. US. Pat. No. 3,277,822.

SUMMARY OF THE INVENTION The present invention provides a data recorder having a very uncomplicated latching mechanism for controlling the spacing between the print head and the bed when the print head .is in a selected closed printing position against the base, so as to place the platen at a precise printing position as determined by the thickness Another object of the invention is to provide latching mechanism for precisely latching the print head against the base at a printing position selected from a plurality of possible positions as determined by the thickness of the form.

Another object of the invention is to provide mechanism for regulating the spacing of the print head in relation to the bed for various thicknesses of forms, which may be incorporated in various types of printing machines and data recorders.

Another object of the invention is to provide means for supporting a printing device and the form to be imprinted on a self-aligning anvil which is arranged for universal pivotal movement to provide for alignment of the anvil to any one of an infinite number of planes coinciding with the printing plane of the platen as determined by the sensed thickness of the printing device and the form.

A feature of the present invention is to provide an inexpensive but reliable and easy to operate data recorder capable of imprinting clear and uniform impressions on a wide variety of business forms having substantial variations in the thicknesses of the form sets.

IN THE DRAWING I the position of the latching mechanism as the print head is unlatched and just starting to move to an open position;

FIG. 4 is similar to FIG. 3 but shows the position of the latching mechanism when the print head is in the open position;

FIG. 5 is a fragmentary view of a self-aligning anvil for supporting a printing plate; and

FIG. 6 is an exploded view of the anvil of FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENT With reference to FIGS. 1 and 2, the data recorder of the present invention comprises a base 10 and a print head indicated generally at 12. The print head 12 is pivotally mounted on the base 10 and is adapted to be moved between an open position shown in FIG. 4, and a closed position of FIG. 2 where it is latched to the base by a latching mechanism indicated generally at 14. In the closed position of the print head 12, a platen carriage indicated at 16 is moved from a home position across the base It) to an actuated position, from right to left as viewed in FIGS. I and 2, to perform a printing stroke. In response to completion of a printing stroke, the print head I2 is released from its latched position and moved to the open position, and the platen carriage 16 is returned to the home position.

The base 10 includes a bed 18 with an anvil 20 for supporting an embossed printing plate thereon. One common form of plate is the popular credit card. Therefore, the plate hereafter will be referred to as a credit card 24. The anvil 20 may be made of a compliant material such as, for example, rubber to afford some degree of compensation for credit cards of various thicknesses.

The print head 12 comprises a pair of side plates 30 and 32 secured together in spaced apart relationship by tie-rods such as 34, and the print head 12 is pivotally supported on a shaft 36 mounted in a pair of bearing members 38 and 40 provided on the bed 18. Each of the side plates 30 and 32 is provided with an elongate slot 42 and 44 respectively, for guiding movement of the platen carriage 16 through a printing operation. Also, each side plate is provided with a sensing pad 31 (only one shown in FIG. 2) adapted to strike the form on the bed 18 when the print head 12 is moved to the closed position thereby terminating the closing action of the print head 12 and spacing the print head from the bed 18 according to the thickness of the form. The platen carriage 16 is best shown in FIGS. 1 and 2, and includes a guide element 46 extending between the side plates 30 and 32 and supported in the elongate slots 42 and 44 in the side plates. Each end of the guide element 46 is provided with an extended runner 48 and 50, adjacent the outer face of each of the side plates 30 and 32 respectively, for supporting a roller platen 52 on a shaft 54. The extended runners 48 and 50 are notched to fit into the slots 42 and 44 so as to provide bearing flanges overlapping the slots and in sliding contact with the side plates. The flanges afford extended bearing surfaces to accurately control and guide the movement of the platen carriage 16 in the slots 42 and 44 and to prevent binding or tilting of the roller platen 52 in its travel through a printing operation. The platen carriage 16 is further provided with an actuating handle 56 for manually moving the platen carriage 16 from the home position to the actuated position to perform a printing stroke.

The latching mechanism 14 employs a pair of latching arms 60 and 62 each adapted to coact with a respective side plate and 32. Because the construction and operation of the latching arms 60 and 62 are identical, only one of the latching arms will be described in detail hereinafter.

As best shown in FIGS. 2-4, the latching arm 60 is pivotally supported on a shaft 64 mounted on the base 10, and projects upwardly through an opening 58 in the bed 18. A torsion spring 66 biases the latching arm 60 in a clockwise direction as viewed in these Figures, to an active position as shown in FIG. 2.

The latching arm 60 includes a camming surface 74. During movement of the print head 12 to the open position, a nose 76 of the side plate 30 rides along the camming surface 74 and pivots the latching arm 60 to an inactive position of FIG. 4 against the bias of the spring 66.

The latching-arm 60 also includes a smoothly curved surface 70 and the side plate 30 is provided with a lock surface 72 adjacent the nose 76. As the print head 12 is moved towards the closed position, the latching arm 60 is pivoted towards the active position until the curved surface 70 comes to rest in mutual engagement with the lock surface 72 at a point within a range over the curved surface 70 as determined by the sensed thickness of the form.

The mutual engagement of the curved surface 70 and the lock surface 72 latches the print head 12 in a precise selected printing position, and it is held tightly in this position against the reaction forces generated by the printing operation of the platen 52. Also, because the curved surface 70 provides a wide range of engagement with the lock surface 72, the print head 12 is effectively latched in any one of an infinite number of selected closed positions.

Further, the angular relationship of the lock surface 72 with respect to the curved surface is such that, when mutually engaged, a force generated by an attempt to move the print head 12 to the open position will fail to create a force component in the latching arm 60 sufficient to move the latching arm 60 to the inactive or unlatched position.

As shown in FIG. 1, actuating means comprising a pair of actuators and 82 are associated with the latching arms 60 and 62 respectively and, because they are similar as in the case of the latching arms 60 and 62, only one of the actuators will be described hereinafter.

With reference to FIGS. 1 and 2, the actuator80 is provided at one end with a flange 84 extending through and guided in the elongate slot 42 in the side plate 30. The flange 84 projects slightly beyond the inside face of the side plate 30. The other end of the actuator 80 is pivotally supported on a rod 86 mounted in the latching arms 60 and 62. As will be further explained below, the actuator 80 releases the latching mechanism 14, by moving the latching arm 60 to the inactive position, to permit movement'of the print head 12' to the open position in response to a printing stroke.

As shown in FIG. 2 the data recorder is also provided with a spring 88, connected to a tie-rod 34 and the shaft 64, for normally biasing the print head 12 to the open position. Additionally, a return spring 90 is connected to a tie-rod 34 and the carriage actuating handle 56 to provide for return of the platen carriage 16 to the home position in response to movement of the print head 12 to the open position.

OPERATION With the print head 12 in the open position of FIG. 4, a credit card 24 is placed on the anvil 20 and a form to be printed (not shown) is placed on the bed 18 in overlying relationship with the credit card.

As the print head 12 is moved towards the closed position against the bias of the spring 88, the nose 76 of the side plate 30 rides upwardly along the camming surface 74 of the latching arm 60 thereby allowing the latching arm 60 to pivot in a clockwise direction as viewed in FIGS. 2-4, to the active position, under the influence of the torsion spring 66. As the sensing pads 31 of the side plates 30 and 32 strike the form on the bed 18, lowering action of the print head 12 is arrested with the roller platen 52 positioned at a selected printing position, and the curved surface 70 of the latching arm 60 has moved under and into locking engagement with the lock surface 72 of the side plate 30 to latch the print head 12 in the closed position. The form is held against movement on the bed 18 by a spring finger 92 fastened on the tie-rods 34 as shown in FIG. 2.

The platen carriage 16 is then moved through a printing stroke to imprint the form. When the platen carriage 16 reaches the actuated position, see FIG. 3., the roller platen 52 strikes the flange S4 of the actuator 80 causing the actuator 80 to be moved leftwardly to pivot the latching arm 60 so as to disengage the curved surface 70 from the lock surface 72. Thereafter, the spring 88 urges the print head 12 towards the open position as the nose 76 of the side plate 30 rides downwardly along the camming surface 74 of the latching arm 60. As shown in FIG. 4, when the print head 12 is in the open position the nose 76 maintains the latching arm 60 in the inactive position against the bias of the torsion spring 66. 1

4, the platen carriage 16 is returned to the home position by the spring 90.

SELF-ALIGNING ANVIL Although the compliant anvil 20 affords some degree of compensation for various thicknesses of credit cards, a preferred anvil arrangement for accommodating a wider range of form and card thicknesses is shown in FIGS. 5 and 6. v

Because the print head 12 is pivoted at one end of the base 10, the thickness of the credit card 24 and the form positioned on a rigid and/or compliant'anvil does not permit latching the print head in the closed position such that the plane of the anvil coincides with a plane defined by movement of the platen 52 in a path through a printing stroke. Accordingly, the anvil of FIGS. 5 and the card and form thicknesses and align the anvil to a plane corresponding to the plane-of the platen 52. Thereafter, the latching mechanism 14 is effective to hold the print head 12and the roller platen 52 ata selected printing position as determined by the thickness of the form sensed by the projections 122, 124 and 126, the platen carriage 16 is moved through a printing stroke to imprint the form, the print head 12 moves to the open position and the platen carriage 16 returns to the home position in readiness for a subsequent printing operation.

6-is arranged for universal pivotal movement to provide for alignment of the anvil'to an infinite number of planes corresponding to the plane of the platen as determined by the thickness of the formand the credit card. Y t

The baseis modified by replacing that portion of the bed 18 underlying the anvil as shown in FIG. 2, with a well 98 comprising a pair of side walls 100 and 102, and repositioning the anvil 20 .to'the left as viewed from the right, of FIG. l so that the anvil 20 is centered between the side plates and 32. As shown in FIGS. 5 and 6, a rocker member 104 is positioned in the well 98'and is pivotally supported on a rod 106 mounted in the side walls 100 and 102. The rocker member 104 is provided with a first set of opposed upstanding ears 108 and 110 for supporting the rocker member 104 on the rod l06, and a second set of opposed upstanding ears I12 and 114 positioned at right angles to the ears 108 and 110.

An anvil 116 is pivotally mounted on the rocker member l04 by means of a bracket 118 secured to the underside of the anvil 116 and supportedon a rod :120

mounted in the ears 112 and 114.

As thus far described, it will be seen thatthe anvil 116 is arranged for universal pivotable movement on a Y -Y axis on the rod 120 and on an XX axis by the rocker member- 104 supported on the rod 106.

The bottom edge of side plate 32 of the side plates 30 and 32 is provided'with a pairof projections 122 and 124 positioned so as to contact the marginal edges of the anvil ll6on the YY axis'when the'print head 12 is closed, and the bottom edge of the' other side plate 30 is provided with a single projection 126 positioned so as to contact'a marginal edge of the anvil 116 on the XX axis. Because plate 30 is eclipsed by plate 32 in FIG. 5, only the projection 126 thereof appears in FIG. 5. These projections replace the sensing pads 31 described hereinabove and, in addition to sensing the form and card thicknesses, coact with the anvil 116 to effect alignment thereof and to lock the anvil 1 16 in the aligned position during a printing operation.

This arrangement provides an anvil which is selfaligning to-an'infinite number of planes. As the print head 12 is pivoted to the closed position, the projections 122, 124 and 126 contact the anvil 116(through the form to be imprinted overlying the anvil) to sensecan be used interchangeably, while maintaining proper parallelism between the print head and the anvil, without requiring independent adjustment and/or critical machining tolerances of the parts. The latching mechanism is positive in operation and provides for latching the print head at any one ofa plurality of selected printing positions and securely holds the print. head in the selected position during a printing operation.

What is claimed is: Y

l. A data recorder for imprinting forms" by means of printing devices in which forms of various thickness may be accepted, comprising; 1 i

I a base;

abed on the base for holding a printing device and a form to be imprinted;

a print head, a pivot mount on thebase for providing movement of said print head between'an open position spaced from the bed and a closed printing position, means for providing an infinite number of possible closed positions within a range spaced from the bed a distance less than the open position;

. a platen supported on theprint head, means for moving said platen across the bed'when the print head said means for providing the infinite number of closed positions including stop means carried by the print head separate from said platen and responsive to movement of the print head towards the closed position for striking the bed in the area which holds a form, said form lying between said stop means and said bed, said stop means terminating the closing action of the print head at a position wherein the platen is spaced from the bed in a printing relationship determined by the form thickness;

a latching arm pivotally mounted on the base;

lock surface carried by said print head on the side.

wherein each segment portion surface serves as a blocking wedge to fit under the lock surface in one particular pivotal position of said print head; whereby; v 1

said print head may be pivoted towards said bed until the stop means abuts the top surface of said form and brings the head to a stop in one of a number of possible positions determined by the thickness of a form on said bed, and said latching arm is pivoted under the lock surface until a segment thereof that fits the space comes to rest between the lock surface and bed, the stop means serving to prevent further closing movement and the latching arm preventing opening movement until displaced from its locking position.

2. A data recorder as set forth in claim 1 which further comprises actuator means associated with the print head and the latching arm for moving the latching arm to a displaced position out of said wedge position in response to a printing stroke.

3. A data recorder'as set forth in claim 1 in which the platen is movable through a printing stroke in a path defining a printing plane, and further comprising:

an anvil on the bed for supporting a printing device and a form to be imprinted in superposed relationship; means for supporting the anvil for universal pivotal movement on an XX and a YY axes to provide for alignment of the anvil to an infinite number of planes;

said stop means for striking the form, when in engagement with the form, acting against the anvil to align the anvil to a plane coinciding with the printing plane of the platen as determined by the thicknesses of the printing device and the form and to lock the anvil in the plane when the print head is in the closed printing position.

4. A data recorder for imprinting forms by means of printing devices in which printing devices and forms of various thicknesses may be accepted, comprising:

a base;

a bed on the base for holding a form to be imprinted;

an anvil on the bed for supporting a printing device underlying the form to be imprinted;

a print head pivotally mounted on the base for movement between an open position spaced from the bed and a closed printing position selected from an infinite number of possible closed positions within a range spaced from the bed a distance less than. the open position;

a platen supported on the print head for movement across the bed through a printing stroke in a path defining a printing plane;

means associated with the print head and responsive to movement of the print head towards the closed position for striking the form and pressing the form and the printing device against the anvil, thereby terminating the closing action of the print head at I one of the selected closed positions wherein the platen is spaced from the bed in a printing relationship determined by the printing device and the form thicknesses;

means for supporting the anvil for universal pivotal movement on an XX and a Y--Y axes to provide for alignment of the anvil to an infinite number of planes;

said means for striking the form, when in engagement with the form, acting against the anvil to align the anvil to a plane coinciding with the printing plane of the platen as determined by the thicknesses of the printing device and theform and to lock the anvil in the plane during movement of the platen through a printing stroke. 

1. A data recorder for imprinting forms by means of printing devices in which forms of various thickness may be accepted, comprising; a base; a bed on the base for holding a printing device and a form to be imprinted; a print head, a pivot mount on the base for providing movement of said print head between an open position spaced from the bed and a closed printing position, means for providing an infinite number of possible closed positions within a range spaced from the Bed a distance less than the open position; a platen supported on the print head, means for moving said platen across the bed when the print head is in said closed position from a home position to an actuated position to perform a printing stroke; said means for providing the infinite number of closed positions including stop means carried by the print head separate from said platen and responsive to movement of the print head towards the closed position for striking the bed in the area which holds a form, said form lying between said stop means and said bed, said stop means terminating the closing action of the print head at a position wherein the platen is spaced from the bed in a printing relationship determined by the form thickness; a latching arm pivotally mounted on the base; a lock surface carried by said print head on the side of said pivot mount opposite the platen travel, said lock surface facing said bed and swingable away from said bed as a result of the pivot position as the print head closes, and movable toward said bed as the print head opens; said latching arm located to swing into the space between said lock surface and bed, said latching arm having a plurality of radial segment portions measured from its said pivot mount producing a generally curved top surface wherein each segment portion differs in length from all other portions, and wherein each segment portion surface serves as a blocking wedge to fit under the lock surface in one particular pivotal position of said print head; whereby, said print head may be pivoted towards said bed until the stop means abuts the top surface of said form and brings the head to a stop in one of a number of possible positions determined by the thickness of a form on said bed, and said latching arm is pivoted under the lock surface until a segment thereof that fits the space comes to rest between the lock surface and bed, the stop means serving to prevent further closing movement and the latching arm preventing opening movement until displaced from its locking position.
 2. A data recorder as set forth in claim 1 which further comprises actuator means associated with the print head and the latching arm for moving the latching arm to a displaced position out of said wedge position in response to a printing stroke.
 3. A data recorder as set forth in claim 1 in which the platen is movable through a printing stroke in a path defining a printing plane, and further comprising: an anvil on the bed for supporting a printing device and a form to be imprinted in superposed relationship; means for supporting the anvil for universal pivotal movement on an X-X and a Y-Y axes to provide for alignment of the anvil to an infinite number of planes; said stop means for striking the form, when in engagement with the form, acting against the anvil to align the anvil to a plane coinciding with the printing plane of the platen as determined by the thicknesses of the printing device and the form and to lock the anvil in the plane when the print head is in the closed printing position.
 4. A data recorder for imprinting forms by means of printing devices in which printing devices and forms of various thicknesses may be accepted, comprising: a base; a bed on the base for holding a form to be imprinted; an anvil on the bed for supporting a printing device underlying the form to be imprinted; a print head pivotally mounted on the base for movement between an open position spaced from the bed and a closed printing position selected from an infinite number of possible closed positions within a range spaced from the bed a distance less than the open position; a platen supported on the print head for movement across the bed through a printing stroke in a path defining a printing plane; means associated with the print head and responsive to movement of the print head towards the closed position for striking the form and pressing the form and the printing device Against the anvil, thereby terminating the closing action of the print head at one of the selected closed positions wherein the platen is spaced from the bed in a printing relationship determined by the printing device and the form thicknesses; means for supporting the anvil for universal pivotal movement on an X-X and a Y-Y axes to provide for alignment of the anvil to an infinite number of planes; said means for striking the form, when in engagement with the form, acting against the anvil to align the anvil to a plane coinciding with the printing plane of the platen as determined by the thicknesses of the printing device and the form and to lock the anvil in the plane during movement of the platen through a printing stroke. 